Update c/image after https://github.com/containers/image/pull/1816

... to work around some of the "unexpected EOF" failures.

Signed-off-by: Miloslav Trmač <mitr@redhat.com>

vendor/golang.org/x/net/http2/flow.go

@@ -18,7 +18,7 @@ type inflow struct {
 	unsent int32
 }
 
-// set sets the initial window.
+// init sets the initial window.
 func (f *inflow) init(n int32) {
 	f.avail = n
 }